Definitions - std102294

DOE-STD-1022-94

Facility One or more building(s) or structure(s), including systems and components, dedicated to common

function (includes operating and non-operating facilities and facilities slated for decontamination and

decommissioning).

Graded Approach An approach where the design, evaluation, and construction process for SSCs require

emphasis commensurate with their mission, cost and potential consequences of failure. Accordingly,

performance categories with specified performance goals ranging from low to extremely low probability of

NPH failure are specified in DOE-STD-1020-2002.

Hurricane intensity Hurricane-type storms are events associated with maximum sustained 1- minute wind

speeds in excess of 75 mph. The U.S. National Weather Service uses the Saffir/Simpson scale to rate the

intensity and the damage potential of hurricanes. This scale is divided into 5 numbers, 1 through 5. Larger scale

numbers represent high wind speeds at which considerable damage occurs.

Liquefaction The sudden loss of shear strength and rigidity of saturated, cohesionless soils, due to steady state

ground water flow or vibratory ground motion. The term seismic liquefaction (or cyclic mobility) is used in

this Standard for liquefaction phenomena associated with seismic motions.

Magnitude A measure of the size of an earthquake. It is related to the energy released in the form of seismic

waves. Magnitude means the numerical value on a standardized scale such as, but not limited to, Moment

Magnitude, Surface Wave Magnitude, Body Wave Magnitude, or Richter Magnitude scale.

Model Building Codes Building codes containing design and construction requirements that apply to normal

commercial buildings (e.g., IBC 2000, International Building Code).

Natural Phenomena Hazard (NPH) An act of nature (for example, earthquake, wind, hurricane, tornado,

flood, precipitation, volcanic eruption, lightning strike, or extreme cold or heat) which poses a threat or danger

to workers, the public, or to the environment by potential damage to structures, systems, and components.

One- (Five-) Hundred-Year Flood A flood level which will be equaled or exceeded with a 1.0 (0.2) percent

chance in any given year.

Performance Category (PC) A classification using a graded approach in which structures, systems, or

components in a category are designed to assure similar levels of protection (i.e., meet the same performance

goal) during natural phenomena hazard events. Five performance categories ranging from 0 to 4 in order of

increasing level of protection have been defined in DOE-STD-1021-93, (e.g., PC-1 for building structures with

potential human occupancy; PC-4 for high hazard facilities such as nuclear power plants).

Performance Goal The mean annual probability of exceedance of acceptable behavior limits used as a target

to develop natural phenomena hazard mitigation requirements. Numerical values for performance goals for

each performance category are provided in DOE-STD-1020.

Probable Maximum Flood The flood that may be expected from the most severe combination of critical

meteorological and hydrologic conditions that are reasonably possible in the drainage basin under study.